The invention relates to a process for removing individual metal sheets from a stack by means of at least one destacking member which seizes the sheet, and for feeding the sheets into a conveyor line. The invention also relates to a device for carrying out the process, and an application of the process.
Known devices for removing sheets from a stack include those shown in FIG. 1 and FIG. 2. In the known device according to FIG. 1, sheets are drawn off one at a time by means of a vacuum arm from the sheet stack arranged above the vacuum arm. The known means for holding the stack of sheets are not shown in FIG. 1. To detach the sheet, the vacuum arm is raised. On then being lowered, the sheet is gripped by the suction cups connected to a vacuum line and is deposited on a transfer table. The suction cups are then released from the sheet and lowered a little further. A pusher arm then pushes the sheet sideways to the feed rolls which convey the sheet away. The destacking device which has just been described is complex and its working rate is limited. FIG. 2 shows another known configuration of a destacking device. In this device also a sheet is drawn off by means of a vacuum arm from a stack arranged above the vacuum arm. The vacuum arm then performs an arc-shaped movement by means of a parallelogram arm-suspension and crank drive, and thereby feeds the sheet to the feed rolls. After this step, the vacuum arm is raised again along the circular arc in order to draw off the next sheet. This arrangement is also limited in its working rate.
Especially in the case of can welding machines, in which the welding can nowadays be performed with very high production rates, there is a need for the individual sheets formed into can bodies and then welded to be supplied at high feed rates. In other applications also, it may be advantageous to use a destacking device with a high working rate.